Lighting with light emitting diodes: let there be light!

There were no absentees from the meeting organised in the Palais de la Bourse by the Lyon CCI on February 9 this year.  All contributors to the CITADEL project were present to mark launching of this program in the presence of Hervé Lefebvre, Head of the ADEME Contract and Energy Efficiency Services Department.  “The purpose of CITADEL is to promote optimum integration of lighting systems using light emitting diodes (LEDs) into buildings, says Christophe Martinsons, head of lighting at CSTB.  This is the first cooperative research operation carried out under the auspices of the "Cluster Lumière".  It has also been approved by the Tenerrdis energy cluster."  LEDs appear to offer considerable progress in the lighting industry.  They are robust, compact, have high energy performance and an exceptionally long life, offer a promising light efficiency and are considered to be a major component of future solutions for indoor and outdoor lighting of buildings.

Towards complete characterisation of LEDs

However, some specific problems related to the integration of LEDs into buildings still need to be studied.  Constraints apply to the visual comfort of users, long term maintenance of performance, conformity with standards and construction regulations, etc.  During the next three years, teams working on the CITADEL project will make a complete characterisation of LEDs and lighting products using the LED technology.  New light quality indices will be investigated for visual comfort and colour rendering.  Clearly defined and reproducible LED analysis protocols will describe methods of making optical and electrical measurements, aging related to environmental stresses, reactions to ultraviolets and all potential degradation mechanisms.  "These physical experimental steps will determine and optimise the effective life of products, and define a global cost of LED lighting solutions, says Christophe Martinsons.  The CITADEL project will also include a study of product life cycles to identify the environmental impact of LED products, from manufacturing to end of life."

A cooperative research project

CITADEL is a consortium formed of laboratories, public research institutions and manufacturers.  Each controls a key aspect of lighting with LEDs.  CSTB coordinates this project co-financed by ADEME and with a total budget of 1.5 M€ over three years.  It carries out its mission in partnership with Philips Lighting, CEA's LETI (Laboratoire d'Electronique et de Technologies de l'Information - Electronics and Information Technologies Laboratory), the LNE (Laboratoire National de métrologie et d'Essais - LNE Metrology and Test Laboratory), the LASH (Laboratoire des Sciences de l'Habitat - Habitat Sciences Laboratory), Ecole Nationale des Travaux Publiques de l'Etat (National Engineering School for State Public Works) and CNRS, and the plasma energy conversion laboratory (LAPLACE, University of Toulouse and CNRS).